Wineglass Bay, Tasmania, Australia. Been there, but not on my own boat...that's unfinished business....
However, this idyllic anchorage, actually in a small extinct crater on the edge of Lake Taupo, which is one humungous volcanic crater, is a place I have personally anchored. Surrounded by virgin native bush - fabulous, and only accessible by boat.
Trouble posting actual pic, so here's the link - click on Satellite view...
http://www.zoomin.co.nz/nz/taupo/kinloch/-boat+harbour/